Volvo 780 Valve Cover Gasket Replacement Cost
How Much Does a Valve Cover Gasket Replacement Cost?
Valve Cover Gasket Replacement Service and Cost
The valve cover is a plastic or metal cover on the top of the cylinder head. Not to be confused with the head gasket, the valve cover gasket seals the surfaces between the valve cover(s) and the cylinder head(s).
The valve cover sits atop the cylinder head, and the valve cover gasket is sandwiched between them to keep circulating oil inside. The majority of valve cover gaskets are molded rubber, tailor fit to the valve cover and mating surfaces. Where applicable, the spark plug tube gaskets are part of the valve cover gasket, and are replaced at the same time.
A vehicle can still be driven with a leaking valve cover, but the leaking oil will cause other problems over time. Spark plug wells can fill with oil, causing a misfire. Oil dripping on coolant hoses will cause them to become soft and eventually burst. And the smell of burning oil will become more noticeable in the cabin. In the most extreme cases, excessive oil leaking onto exhaust manifolds can cause a fire.
Repair intervals vary greatly by vehicle and driving conditions. The valve cover gasket does not wear like a tire or a ball joint, but eventually the gasket's rubber or cork will degrade to the point of leakage. Often, leakage of the valve cover gasket is visible during normal servicing (such as an oil change) so it typically doesn't go unseen for too long.
Valve Cover Gasket Replacement Repair Information
It is easiest to spot oil leaks when they are new or fresh. The technician may clean the fluid around the leak and direct you to come back later to confirm where the leak is coming from. With more progressed oil leaks, the technician will also add a dye to the oil. After the vehicle has been driven with the dye, a UV light will be used to pinpoint the leakage and recommend repair.
The technician will remove the valve cover, remove the old gasket, and clean all gasket surfaces before installing the new valve cover gasket. On some engines, removal of the intake manifold, or other major parts may be required in order to access the fasteners on the cover. After completion, the area will be checked for leaks.
A high quality gasket should be used. Often, the OEM gasket will have the best seal. Some manufacturer suggest adding special silicone to specific areas to ensure a proper seal. Where applicable, a valve clearance inspection and adjustment should be performed.
Some modern engines have multi-piece valve covers with integrated parts, such as PCV Valves or coil pack holders. Increasingly, they are also made of plastic. Proper care should be taken so as not to damage this style of cover. The leak itself should also be properly diagnosed, as it is not uncommon for the valve cover itself to come apart, and require complete replacement.
Repairing your own car is an extremely rewarding process that can also save you money. But before you dive in, it’s important to be sure the issue has been properly diagnosed. Seemingly obvious symptoms can lead the inexperienced down a rabbit hole of replacing parts that don’t fix the problem. Proper diagnosis can save more money than guessing at what’s broken! If you're unsure you have the right tools or experience to diagnose a problem, consider reaching out to a RepairPal Certified Shop. The vast majority of Valve Cover Gaskets only require simple tools to replace. However, the procedures vary wildly from car to car. Prior to ordering parts or attempting this repair yourself, look online for guides on how to replace the part in your specific vehicle. Some will require significant disassembly of the top end of the engine in order to remove the Valve Cover. Specific torque specifications and torquing sequences should also be observed to prevent damage to the Valve Cover or gasket.